Tanning plant



HANS HUNI Sept. 16, 1969 TANNING PLANT 2 Sheets-Sheet 1 Filed July 10, 1967 ?24 iso l 26 X 23 1 I NVENTOR HANS NON! 7 United States Patent O 3,466,904 TANNENG PLANT Hans Huni, Ebnetstrasse 38, Horgen, Switzerland Filed July 10, 1967, Ser. No. 656,620 Clams priority, application Switzerland, July 11, 1966, 10,143/ 66 Int. Cl. C14c 3/00 U.S. Cl. 69-30 3 Claims ABSTRACT OF THE DISCLOSURE A tanning plant having a horizontal rotating tanning drum provided with a hollow axle journal containing a coupling member, located in the end face of the drum, and a shielded outlet device for the drum, a controllable pressure source connected by a pipe located in the hollow axle journal to permit a combined suction and pressure elfect to flow the liquid in the drum through the outlet device, a slide or gate valve for the outlet device pneumatically operable by means of a plunger, wherein the coupling member is formed with a tapped hole for receiving the threaded hub of a first disc, rotatable relative to a second disc, both discs provided with concentric annular grooves whose cross-sections form connected channels.

The present invention relates to a tanning plant with a rotating tanning drum. As is well known, the tanning process carried out in rotating tanning drums by means of suitable solutions has to be interrupted after a precisely predetermined period, which is efiected by emptying the drum. In conventional tanning plants this emptying of the drum is a relatively complicated and time-consuming process; the drive of the drum has to be interrupted and the drum has to be turned into such a position that the discharge opening provided is downwardly directed; the discharge of the solution of the drum, after this outlet is manually opened, is always carried out by means of gravity. The assessment of the correct moment for emptying, required high skill on the part of the operating personnel and allowances have to be made for relatively long stopping periods, particularly if the operating personnel is not working shifts.

The object of the present invention is to eliminate these drawbacks by designing the plant in such a manner that automation and hence 24-hour operation is made possible; this not only facilitates the operational working, but also allows the moment of emptying to be precisely adhered to and the emptying time to be reduced to a minimurn.

For this purpose the tanning plant according to the invention is characterised by an outlet device in the horizontal drum, located in the region of the face at one end of the drum and shielded against the collection chamber of the skins to be tanned, and connected, by means of a pipe located in a hollow axle journal of the drum, to a controllable pressure source outside the drum, whose suction effect and pressure effect make is possible for the solution to flow out from the drum.

The outlet device may be an outlet opening located in the end face of the casing of the drum and having pneumatically operated slides, whereby it is possible to have separate air conduits, in order to open and close the slide or gate valves, in the hollow axle journal of the drum and to supply a compressed air source which is operable by means of a time control or a punched card; in this construction the tanning drum is usefully provided with a limit switch, which influences the drum-drive and guarantees that the outlet opening is at the bottom when the slide closes.

3,466,904 Patented Sept. 16., 1969 ice In another embodiment of the invention the outlet device is provided with a suction tube, which is radally located in the region of the face at one end of the drum and whose outlet is directed towards the drum casng. This suction tube is coupled to a pipe in the hollow axle journal and is led outwards to a circulating pump, from which a branch -pipe with two reversible two-way acting valves, which are arranged in series, lead to a pipe through the other hollow axle journal of the tanning drum; the two-way acting valve which is closer to the pump has a connection for a discharge pipe for the solution and the other two-way acting valve has a feed pipe for the solution. Such an arrangement makes it possible to circulate the solution continuously during the tanning process and to carry out the emptying and the filling of the drum whilst the latter rotates.

Two examples of the plant according to the invention are illustrated in the accompanying drawings, in which:

FIG. 1 is a side view partly in section of a drum according to this invention;

FIG. 2 is an end View of the drum according to FIG. 1;

FIG. 3 is a side view of an alternative Construction; and

FIGS. 4 and 5 are detailed sectional views of the aXle journals in accordance with this invention.

The tanning plant which is schematiaclly llustrated in FIGS. 1 and 2 comprises a tanning drum 1 which, by means of axle journals 2, 3, is rotatable in standards 4. The drum 1 is in connection with controllable driving means (not illustrated), which permit a constant rotation of the drum. In the casing of the drum there is provided a closable feed opening 5, through which the skins to be tanned can be inserted and removed from the drum and through which the tanning solution can be poured. The axle journal 2 (in FIG. 1 on the right hand side) is hollow; it is provided with a coupling member 6 having two separate channels 7a, 7b and corresponding inner and outer connections. The connections on the outer end portion of the coupling member 6 are each connected to a pressure line Sa and 9a respectively, and the ones on the inner end portion of the coupling member 6 are each connected to a corresponding pressure line 8b and 9b respectively. The coupling member 6 guarantees the permanent connection of the pressure lines Sa, 9a to the associated channels 7a and 7b and thus to the pressure lines 8b, 9b which are flexible hoses. These pressure lines Sb, 9b lead outwards from the inside of the drum through a (sealed) pressure guide 10' on the end face, and discharge on either side of on Operating plunger into a cylinder 11. A closing slide (not illustrated) is coupled to the said plunger, which works with a discharge opening 12 on the end face and near the drum circumference. Both pressure lines Sa, 9:1 are connected to a compressed air pipe 14 over a magnetic valve 13. The valve housing is also equipped with a pressure release outlet 15.

The hoses 8b, 9b inside the drum and the discharge opening 12 are shielded from the tanning chamber of the drum 1 by a perforated wall 16, so that the skins in the tanning chamber do not contact the pressure hoses 817, 9b during the rotation of the drum and hence cannot block the discharge opening 12.

During the operation of the described plant, the drum 1 is rotated. The valve 13, which, e.g. for automatic operation can be operated by a punched card or by a time switch, is positioned in such a manner that the pipe Sa, 7a, Sb is under pressure and the slide keeps the opening 12 closed, whilst the pipe 9a, 7b, 9b is in connection with 'the pressure release outlet 15 of the valve 13. After the completion of the tanning process the valve 13 is switched over in such a manner that the pipe sa, 7a, 9b is under pressure, which causes the slide to free the opening 12, whilst the other pipe 9a, 7b, 9b is vented. At the same time the drum drive has been interrupted by a limit switch (not illustrated) in such a manner, that the discharge opening 12 is directed downwards when the drum 1 is stopped. In addition thereto, means may also be provided which permit the tanning chamber of the drum to be pressurised in such a manner that the emptying process is speeded up; as an example, a pressure pipe could be arranged through the axle journal 3 and discharge into the interior of the drum.

FIG. 4 illustrates a variation of the coupling member 6 of FIG. 1 on an enlarged scale. The coupling member 6 has a cylinder portion 40, which extends through the hollow axle journal 2 and is rigidly connected outside to the clearing bracket 4 by means of strut 41. The end of the cylinder portion 40 which extends into the drum 1 has a tapped hole, into which is screwed an axial threaded coupling of a disc 42. Adjacent to this disc 42 is a second disc 43, to which is connected a circumferential ring 44 which overlaps the disc 42. The parts 43, 44 are rotatable relative to the disc 42 and are connected to the rotatable drum 1 by means of a strut 45. The two pipes 47a, 47b (corresponding to the pipes 7a, 7b of the embodiment of FIG. 1) lead through the cylinder portion 40 and are in connection with corresponding channels 48a, 48b in the disc 42. To the pipes 47a, 47b are coupled the pipes 58a, 59a (corresponding to the pipes 8a, 9a of FIG. 1). Each of the two channels 48a, 48b extends into an annular groove 50a, 50b in the disc 42 and is concentrc to the axis a of the drum; these annular grooves 50a, 50b have a semi-circular cross-section and are made into an annular channel of circular cross-section by corresponding annular grooves 51a, 511) on the adjacent end faces of the disc 43. The annular channel 50a, 51a is in connection with a channel 52a in the disc 43 and leads outwards through the circumferential ring 44 whilst, similarly, from the annular channel 50b, 51b a channel 52b in the disc 43 leads outwards through the circumferential ring 44. The channel 52a is connected to a pipe 591) (corresponding to pipe 9b in FIG. 1) and the channel 52b is connected to a pipe 58b (corresponding to pipe Sb in FIG. 1). In order to satisfactorily seal the annular channels 50a, Sla and 50b, 51b towards the exterior there are provided further concentric annular channels in the discs 42, 43 which are rotatable relative to each other, in each of which there is arranged a scaling ring 60. Due to the design of the coupling member 6 the pipes 58a, 59a during rotation are in permanent connection with the pipes 58b and 59b, so that the control of the slide (here not illustrated) can be eected in similar manner `to the example according to FIG. 1.

In many cases it is desired to be able to take samples from the tanning solution in the drum 1. For this purpose there may be provided four pipes instead of only two pipes (serving the pneumatic slide control) through the coupling member 6, one of which serves for the removal and the other one for the return feed of the solution sample. Naturally corresponding additional annular channels in the discs 42, 43 have to be provided in such a case. Such a pipe system which serves for removing and feeding back the solution can also be used for heating, or cooling the solution outside the drum, or admixed materials can be added to the solution.

Since it is usual to arrange several tanning drums coaxially adjacent to each other, the unused space between the hearing brackets of adjacent drums should be as small as possible; in this case the arrangement illustrated in FIG. 4 is particularly practical. However, where there is suflicient space between the drums, the variation illustrated in FIG. can also be used. The coupling member 6 itself is identical to the one shown in FIG. 4 and only the assembly is different. Here, the cylinder portion 40 with the exterior tapped hole is inserted into the axle journal 2 of the drum 1 and is rigidly connected with the latter; 'the disc 43 with the circumferential ring 44 of the discs 42, 43

which are arranged outside the drum, is rigidly connected to the bearing bracket 4 by means of a strut 55. Naturally the connection of the pipes 58a, 59a and 58b, 5917 is also suitably chosen in this case, i.e. the pipes 58a, 59a are connected to the channels 52b, 52a and the pipes 58b, 59b are connected to the pipes 47a, 47b. The function of the coupling member 6 is the same as in the arrangement according to FIG. 4.

The tarning plant illustrated in FIG. 3 has similar to 'the first embodiment, a tanning drum 21, which, by means of axle journals 22 and 23, is rotatably mounted on standards 24. On both end faces of the drum 21 two end chambers are shielded from the central tanning chamber of the drum 21 by perforated walls 26. The two axle journals 22, 23 are designed as hollow shafts. Through each of these axle journals there is provided, in the drum end chambers and radially extending against the circumferential wall of the drum, a pipe 27a and 27b to which there are coupled pipe fittings 28a and 28b; the externally extending pipe 27a is connected to the suction side of a pump 30, whose pressure side is in connection wtih a three-way acting slide 32 over a measuring instrument 31, which in turn is equipped with a heating means. From this three-way slide 32 a discharge pipe 33 is led to a collecting vessel (not illustrated) and a circulating pipe 34 is led to a second three-way acting slide 35, which on the one side is connected to a supply line 36 and on the other side to a pipe 27b in the axle journal 23. Both three-wayacting slides 32 and 35 are controllable by means (not illustrated) e.g. by means of a punched card or a time switch.

When Operating the described arrangement, the drum 21 is rotated by driving means (not illustrated). The two three-way acting slides 32, 35 are positioned in such a manner that the pump 30 continuously circulates the tanning solution through pipes 28a, 27a, measuring instrument 31, circulating pipe 34, pipes 27b, 28b and the drum 21. The Chemical and physical characteristics (eg. pH- value consistence etc.) can be measured continuously in the measuring instrument 31 and can be corrected, if necessary, by suitable additives through the supply line 36 and, for example, the acid content and the temperature of the tanning solution can be regulated to the desired values. After the completion of the tanning process the three-way acting 32 is automatically reversed by the time control means, so that the pipes 28a, 27a are connected with the discharge pipe 33 over the pump 30, which causes a forced emptying of the drum 21.

The main advantage of the described arrangements is that the tanning drum can be automatically emptied precisely at the correct moment and without any complicated action on the part of the Operating personnel, whereby the drum is forced into the correct emptying position, as in the first example, or as in the second example, can continue to be rotated. Hence it is possible to use the tanning drums in 2,4-hour Operations and the need for attendance remains minimal.

What is claimed is:

1. A tanning plant with a horizontal rotating tanning drum having at least one hollow axle journal and an outlet device for the drum, located in the region of 'the end face of the drum provided with said axle journal and shielded against a collection chamber to the skins to be tanned, comprising a controllable pressure source outside the drum, said device being connected by a pipe located in the hollow axle journal of the drum to said pressure source, the combined suction and pressure eifect of said source enable liquid to flow out from the drum, said outlet device having a valve means on the end face, a plunger for pneumatically Operating the slide means, separate pressure lines connecting to the two sides of the plunger, a compressed-air pipe coupled thereto, a coupling member in the axle journal, and a reversing valve provided with a pressure release outlet, in which the coupling member has a cylinder portion extending through the hollow axle journal of the drum, which has an aXial tapped hole on one end, a first disc having a threaded hub positioned in said axial hole, a second disc positioned adjacent the first disc, said first disc being rotatable relative thereto, the adjacent end faces of said discs provided With concentric annular grooves having cross-sections forming annular Channels, each of which is connected to a channel extending in the first disc, and in the cylinder portion and to a channel in the second disc.

2. Tanning plant according to claim 1, in which means are provided for securing the cylindrical portion of the coupling member against rotation, said cylindrical portion having an end carrying the first disc, extending into the drum, and means for rotatably connecting the second disc to the drum.

3. Tanning plant according to claim 1, Wherein the cylindrical portion of the coupling member is rotatably connected to the drum, said cylindrical portion having an end carrying the discs, projecting outside the drum,

and means for securing the second disc against rotation References Cited UNITED STATES PATENTS 7/ 1906 Wilkinson 251-62 X 8/1909 Hosford 251-62 X 10/ 1943 Zimarik 68-144 8/ 1949 Buss 68-139 10/1951 Buss 68 X 2/1954 Kling et al. 68-144 1/1963 Peel 68-139 X 1/1965 Rossi 69--30 10/1967 Quinn et al 69--30 FOREIGN PATENTS 12/ 1943 Great Britain.

ALFRED R. GUEST, Primary Examiner.

U.S. Cl. X.R. 

